def find_max(ls,left, right):
    if left == right:
        return ls[left]
    t1=find_max(ls,left,(left+right)//2)
    t2=find_max(ls,(left+right)//2+1,right)
    if t1>t2:
        return t1
    else:
        return t2



if __name__ == "__main__":
    ls = list(map(int, input().strip().split()))
    print(find_max(ls,0, len(ls)-1))
